Aircraft Composite-Metal Joint Bushing Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for joining fibre composite plastics with metal components in aircraft construction face challenges such as complex installation processes, high costs, difficulty in achieving aerodynamic requirements, and issues with lightning strike protection, particularly with sleeve rivets, which also impair the visual appearance and sealing integrity of wing components.
Innovation Solution
A structural assembly using an electrically conductive bushing with a collar and depression, allowing for a secure press fit and electrical connection, combined with a connecting element that provides a smooth surface for painting and fluid sealing, utilizing a universal bushing that can accommodate components of varying thicknesses and materials, and incorporating a locking ring connector for mechanical joining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sleeve rivets are used for joining fibre composite plastics with metal components, then a secure mechanical connection is achieved, but the installation process becomes complex and costly
Solution Approach 1:
The connecting element is divided into a bushing (secured in the hole) and a separate connecting element (inserted into the bushing). This segmentation allows the bushing to be pre-installed and secured, simplifying the overall installation process while maintaining connection strength.
Solution Approach 2:
The bushing acts as an intermediary component between the fibre composite plastic and metal components. It provides a simplified interface that facilitates easier installation compared to direct sleeve rivet installation, reducing installation complexity while maintaining structural integrity.
2Strength
If sleeve rivets are used for joining components, then mechanical connection is achieved, but aerodynamic requirements and sealing integrity become difficult to ensure
Solution Approach 1:
The depression in the bushing creates a localized recess that accommodates the connecting element's head, ensuring that the surrounding surface remains smooth and aerodynamic. This local modification allows the connecting element to be securely installed while maintaining the overall surface quality required for aerodynamic performance and sealing integrity.
3Reliability
If sleeve rivets are used for joining, then electrical connection for lightning strike protection is achieved, but the visual appearance and surface smoothness are impaired
Solution Approach 1:
The depression in the bushing provides a localized area that accommodates the connecting element's head, ensuring the surrounding surface remains smooth and aerodynamic. This allows the electrical connection for lightning strike protection to be maintained while the surface appearance is preserved for painting and aerodynamic requirements.
4Strength
If conventional connecting elements are used, then mechanical joining is achieved, but components of varying thicknesses require different connecting elements
Solution Approach 1:
The bushing is designed with a depression that can accommodate connecting elements of different lengths. This universal design allows a single bushing type to be used with components of varying thicknesses, eliminating the need for multiple specialized connecting elements and simplifying inventory and installation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a cost-effective, aerodynamically advantageous, and electrically conductive structural assembly that can be painted smoothly, ensuring reliable electrical connections and fluid-tight sealing, while reducing the risk of delamination and material thickness discrepancies, thus improving the integrity and appearance of aircraft components.
Implementation Method 1
The bushing is secured by radial expansion in a through hole of the components to be joined together by means of a press fit
Implementation Method 2
an electrically conductive bushing is secured in a through hole through the components... an electrically conductive surface entity... an electrical connection exists between the at least two components
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention concerns a connecting arrangement (14) for joining together at least two components (10, 12) to form a structural assembly (16), in particular in the region of a wing of an aircraft, wherein at least one component (10) is formed from a fibre composite plastic and at least one further component (12) is formed from a metal, or at least two components (10) are formed from a fibre composite plastic. In accordance with the invention a bushing (22) is secured in a through hole (20) through the components (10, 12), and a first end (26) of the bushing (22) is provided with a collar (30), which faces towards a lower face (32) of the structural assembly (16), and a second end (28) of the bushing (22) and a zone (34) of an upper face (36) of the structural assembly (16) radially surrounding this end (28) have a depression (38), and a connecting element (50) is installed in the bushing (22). By this means there ensues, inter alia, a smooth, aerodynamically beneficial configuration of the upper face (36), which can be provided with a coating without any problems, and which ensures a reliable electrical contact between the connecting element (50) and a conductive surface entity (18) of the first component (10). Furthermore the invention concerns a method, in particular for the purpose of manufacturing such a connecting arrangement (14).